Internal combustion engine control system

Abstract

Electrical circuitry including a single absolute pressure transducer that is arranged to be exposed to substantially atmospheric pressure during a selected associated internal combustion engine operating condition produces an electrical pressure value indicating signal that is stored only when the pressure transducer is exposed to substantially atmospheric pressure. An electronic data processor unit preprogrammed to calculate a selected engine operating parameter value for the associated engine is preprogrammed to periodically effect a predetermined atmospheric pressure correction of the selected engine operating parameter value when the stored electrical pressure value indicating signal differs in a selected sense from a preselected value.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. In an internal combustion engine control system of the type that employs electrical signal representations of engine manifold pressure and atmospheric pressure to effect engine control, an engine intake passage through which air is supplied to said engine;   a valve located in said intake passage that is selectively adjustable between closed and maximum open positions for controlling the amount of air flow to said engine;   a port in said intake passage so positioned relative to said valve that said port is exposed to substantially atmospheric pressure when said valve is in said closed position and to engine manifold pressure when said valve is not in said closed position;   means for producing an electrical pressure valve indicating signal, said means including at least a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said port for sensing substantially atmospheric pressure when said valve is in said closed position and engine manifold pressure when said valve is not in said closed position;   memory means; and   circuit means for effecting the loading of said electrical pressure valve indicating signal into said memory means when said valve is in said closed position.   
     
     
       2. In an internal combustion engine control system of the type that employs digital representations of engine manifold pressure and atmospheric pressure to effect engine control, an engine intake passage through which air is supplied to said engine;   a valve located in said intake passage that is selectively adjustable between closed and maximum open positions for controlling the amount of air flow to said engine;   a port in said intake passage so positioned relative to said valve that said port is exposed to substantially atmospheric pressure when said valve is in said closed position and to engine manifold pressure when said valve is not in said closed position;   a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said port for sensing substantially atmospheric pressure when said valve is in said closed position and engine manifold pressure when said valve is not in said closed position;   means for converting said output signal of said pressure transducer to a digital representation of the sensed pressure value;   a digital memory means; and   circuit means for effecting the loading of said digital representation of the sensed pressure value into said memory means when said valve is in said closed position.   
     
     
       3. An internal combustion engine control system for use with internal combustion engines having an intake passage through which air is supplied to the engine and a valve located in the intake passage that is selectively adjustable between closed and maximum open positions for controlling the amount of air flow to the engine comprising: a port in said intake passage so positioned relative to said valve that said port is exposed to substantially atmospheric pressure when said valve is in the closed position and to engine manifold pressure when said valve is not in said closed position;   means for producing an electrical valve position indicating signal of a selected potential level that indicates said valve is in said closed position;   means for producing an electrical pressure value indicating signal, said means including at least a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said port for sensing substantially atmospheric pressure when said valve is in said closed position and engine manifold pressure when said valve is not in said closed position; and   an electronic data processor unit that is preprogrammed to calculate a selected engine operating parameter value for an associated internal combustion engine, said program including at least one periodically performed atmospheric pressure correction determining routine that is preprogrammed to sense said electrical valve position indicating signal, to determine if said valve is in said closed position, to read and store said electrical pressure value indicating signal when said valve is in said closed position and to skip said read and store steps when said valve is not in said closed position, to read a stored said electrical pressure value indicating signal, to determine if the stored said electrical pressure value indicating signal so read differs in a selected sense from a preselected value and to effect a predetermined atmospheric pressure correction of said selected engine operating parameter value when the stored said electrical pressure value indicating signal to read differs in said selected sense from said preselected value.   
     
     
       4. An internal combustion engine control system for use with internal combustion engines having an intake passage through which air is supplied to the engine and a valve located in the intake passage that is selectively adjustable between closed and maximum open positions for controlling the amount of air flow to the engine comprising: a port in said intake passage so positioned relative to said valve that said port is exposed to substantially atmospheric pressure when said valve is in the closed position and to engine manifold pressure when said valve is not in said closed position;   means for producing an electrical valve position indicating signal of a selected potential level that indicates said valve is in said closed position;   a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said port for sensing substantially atmospheric pressure when said valve is in said closed position and engine manifold pressure when said valve is not in said closed position;   means for converting said output signal of said pressure transducer to a digital representation of the sensed pressure value; and   an electronic data processor unit that is preprogrammed to calculate a selected engine operating parameter value for an associated internal combustion engine, said program including at least one periodically performed atmospheric pressure correction determining routine that is preprogrammed to sense said electrical valve position indicating signal, to determine if said valve is in said closed position, to read and store said digital representation of the sensed pressure value when said valve is in said closed position and to skip said read and store steps when said valve is not in said closed position, to read a stored said digital representation of the sensed pressure value, to determine if the stored said digital representation of the sensed pressure value so read differs in a selected sense from a preselected value and to effect a predetermined atmospheric pressure correction of said selected engine operating parameter value when the stored said digital representation of the sensed pressure value so read differs in said selected sense from said preselected value.   
     
     
       5. An internal combustion engine control system comprising: an engine port and valve combination arranged in such a manner that said valve is effective to expose said engine port to substantially atmospheric pressure and to engine manifold pressure as determined by selected respective engine operating conditions;   means for producing an electrical valve position indicating signal of a first potential level that indicates said engine port is exposed to substantially atmospheric pressure and of a second potential level that indicates said engine port is exposed to engine manifold pressure;   means for producing an electrical pressure value indicating signal, said means including at least a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said engine port; and   an electronic data processor unit that is preprogrammed to calculate a selected engine operating parameter value for an associated internal combustion engine, said program including at least one periodically performed atmospheric pressure correction determining routine that is preprogrammed to sense said electrical valve position indicating signal, to determine if said engine port is exposed to substantially atmospheric pressure, to read and store said electrical pressure value indicating signal when said engine port is exposed to substantially atmospheric pressure and to skip said read and store steps when said engine port is exposed to engine manifold pressure, to read a stored said electrical pressure value indicating signal, to determine if the stored said electrical pressure value indicating signal so read differs in a selected sense from a preselected value and to effect a predetermined atmospheric pressure correction of said selected engine operating parameter value when the stored said electrical pressure value indicating signal so read differs in said selected sense from said preselected value.   
     
     
       6. An internal combustion engine control system comprising: an engine port and valve combination arranged in such a manner that said valve is effective to expose said engine port to substantially atmospheric pressure and to engine manifold pressure as determined by selected respective engine operating conditions;   means for producing an electrical valve position indicating signal of a first potential level that indicates said engine port is exposed to substantially atmospheric pressure and of a second potential level that indicates said engine port is exposed to engine manifold pressure;   a single absolute pressure transducer of the type that produces an output electrical signal that is a function of absolute pressure value in operative communication with said port;   means for converting said output signal of said pressure transducer to a digital representation of the sensed pressure value; and   an electronic data precessor unit that is preprogrammed to calculate a selected engine operating parameter value for an associated internal combustion engine, said program including at least one periodically performed atmospheric pressure correction determining routine that is preprogrammed to sense said electrical valve position indicting signal, to determine if said engine is exposed to substantially atmospheric pressure, to read and store said digital representation of the sensed pressure value when said engine port is exposed to substantially atmospheric pressure and to skip said read and store steps when said engine port is exposed to engine manifold pressure, to read a stored said digital representation of the sensed pressure value, to determine if the stored said digital representation of the sensed presure value so read differs in a selected sense from a preselected value and to effect a predetermined atmospheric pressure correction of said selected engine operating parameter value when the stored said digital representation of the sensed pressure value so read differs in said selected sense from said preselected value.